/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package reduce

import (
	"time"
)

import (
	"github.com/pkg/errors"

	"github.com/shopspring/decimal"
)

var _ Reducer = (*sumReducer)(nil)

type sumReducer struct{}

func (s sumReducer) Int64(prev, next int64) (int64, error) {
	return prev + next, nil
}

func (s sumReducer) Float64(prev, next float64) (float64, error) {
	return prev + next, nil
}

func (s sumReducer) Decimal(prev, next decimal.Decimal) (decimal.Decimal, error) {
	return prev.Add(next), nil
}

func (s sumReducer) Time(_, _ time.Time) (ret time.Time, err error) {
	err = errors.New("time.Time is not supported for SUM")
	return
}
